<fieldset>
    <?php
    echo $this->Form->create('Cocktail');

    echo $this->Form->input('Cocktail.id', array(
        'label' => __('<h1>Cocktails</h1>', true),
        'empty' => __('Cocktail Auswahl', true),
        'options' => $cocktails
    ));

    echo $this->Ajax->observeField('CocktailId', array(
        'url' => array('action' => 'select'),
        'frequency' => 0.1,
        'update' => 'info'
            )
    );

    echo $this->Form->end();
    ?>

</fieldset>
<div id="info">

</div>